June i 2, 1884] 



NA TURE 



i59 



has received an enormous development, and whose application 

 appears to offer a rich harvest of results. I refer to the applica- 

 tion of photography to astronomical observation. 



Your respected member, Mr. De la Rue, is the father of this 

 method, 'lime does not permit me to dwell on his early 

 endeavours and his successful results, but they are well known 

 to you all. He opened up the field, and he cleared the way for 

 his successors. 



The recent strides in the chemistry of photography and the 

 production of dry plates of extreme sensibility have permitted 

 the application of the method to objects that formerly could not 

 be photographed. Here, on the screen, are the spectra of stars 

 photographed directly from the stars by Dr. Huggins, the lines 

 which tell of the chemical constitution and temperature of the 

 star's atmosphere being sharply defined. 



Here are photographs of the great comet of 1882, which, with 

 the cooperation of Mr. Allis of Mowbray, I obtained at the 

 Cape, by attaching his ordinary camera to an equatorially 

 mounted telescope, and with its aid following the comet exactly 

 for more than two hours. Each one of the thousands of points 

 of light that you see is the picture of a fixed star. The photo- 

 graph suggests the desirability of producing star maps by direct 

 photography from the sky. 



Here on the screen is a photograph of the great nebula of 

 Orion, or rather a series of photographs of it made by Mr. 

 Common of Ealing. You will note the gradual development of 

 detail by increase of exposure, and the wonderful amount of detail 

 at last arrived at. Here are photographs from drawings of the 

 same, and you will note the discrepancies between them. And 

 here is a photograph of a star cluster also by Mr. Common. 



No hand of man has tampered with these pictures. They 

 have a value on this account which gives them a distinct and 

 separate claim to confidence above any work in which the hand 

 of fallible man has had a part. 



The standpoint of science is so different from that of art. A 

 picture which is a mere copy of nature, in which we do not 

 recognise somewhat of the soul of the artist, is nothing in an 

 artistic point of view ; but in a scientific point of view the more 

 absolutely that the individuality of the artist is suppressed, and 

 the more absolutely a rigid representation of nature is obtained, 

 the better. 



Here is a volume compiled by one of the most energetic and 

 able of American astronomers — Prof. Holden. It contains 

 faithful reproductions of all the available drawings that have been 

 made by astronomers of this wonderful nebula of Orion from the 

 year 1656 to recent times. 



If now we were to suppose one hundred years to elapse, and 

 no further observation of the nebula of Orion to be made 

 in the interval ; if in some extraordinary way all previous obser- 

 vations were lost, but that astronomers were offered the choice 

 of recovering this photograph of Mr. Common's, or of losing it 

 and preserving all the previous observations of the nebula re- 

 corded in Prof. Holden's book — how would the choice lie ? I 

 venture to say that the decision would be — Give us Mr. Common's 

 photograph. 



Is it not therefore now our duty to commence a systematic 

 photographic record of the present aspect of the heavens ? Will 

 not coming generations expect this of us ? Does not photography 

 offer the only means by which, so far as we know, man will be 

 able to trace out and follow some of the more slowly developing 

 phenomena of sidereal astronomy? 



Huggins has shown how the stars may be made to trace in the 

 significant cipher of their spectra the secrets of their constitution 

 and the story of their history. Common has shown us how the 

 nebula? and clusters may be separately photographed, and it is 

 not difficult to see how that process may be applied, not only to 

 special objects, but piece by piece to the whole sky, till we 

 possess a photographic library of each square half-degree of the 

 heavens. But such a work can only be accomplished by con- 

 summate instruments, and with a persistent systematic continuity 

 which the unaided amateur is unable to procure and to employ. 

 It is a work that must be taken up and dealt with on a national 

 scale, on lines which Huggins and Common have so well indi- 

 cated, and which has already been put in a practical form by a 

 proposal of Norman Lockyer's at a recent meeting of the Royal 

 Astronomical Society. 



I would that I had the power to urge with due force our duty 

 as a nation in this matter, but my powers are inadequate to the 

 task. 



I employ rather the words of Sir John Herschel, because 



no words of mine can equal those of him who was the prose- 

 poet of our science, whose glowing language was always as just 

 as it was beautiful, and whose judgment in such matters has 

 never been excelled. They were spoken in the early days of 

 exact sidereal astronomy, when the strongholds of space were 

 but beginning to yield the secret of their dimensions to the un- 

 tiring labour and skill of Bessel, of Struve, and of Henderson. 

 Think what they would have been now when they might have 

 told how Huggins' spectroscope had determined the kinship of 

 the stars with our sun, how it had so far solved the mysteries of 

 the constitution of the nebula;, and pointed out the means of 

 determining the absolute velocity of the celestial motions in the 

 line of sight. Think what Herschel would have said of those 

 photographs by Common that we have seen to-night of that 

 nebula that Herschel himself had so laboriously studied, and 

 whose mysterious convolutions he had in vain endeavoured ade- 

 quately to portray ; and think of the lessons of opportunity 

 and of duty that he would have drawn from such discoveries, as 

 you listen to his words spoken forty-two years ago : — 



" Such results are among the fairest flowers of civilisation. 

 They justify the vast expenditure of lime and talent which have 

 led up to them ; they justify the language which men of science 

 hold, or ought to hold, when they appeal to the Governments of 

 their respective countries for the liberal devotion of the national 

 means in furtherance of the great objects they propose to accom- 

 plish. They enable them not only to hold out but to redeem 

 their promises, when they profess themselves productive labourers 

 in a higher and richer field than that of mere material and 

 physical advantages. 



" It is then, when they become (if I may venture on such a 

 figure without irreverence) the messengers from heaven to earth 

 of such stupendous announcements as must strike every one 

 who hears them with almost awful admiration, that they may 

 claim to be listened to when they repeat in every variety of 

 urgent instance that these are not the last of such announcements 

 which they shall have to communicate, that there are yet behind, 

 to search out and to declare, not only secrets of nature which 

 shall increase the wealth or power of man, but truths which 

 shall ennoble the age and country in which they are divulged, 

 and, by dilating the intellect, react on the moral character of 

 mankind. Such truths are things quite as worthy of struggles 

 and sacrifices as many of the objects for which nations contend, 

 and exhaust their physical and moral energies and resources. 

 They are gems of real and durable glory in the diadems of 

 princes, and conquests which, while they leave no tears behind 

 them, continue for ever unalienable." 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Cambridge. — The following are among the Readers and 

 University Lecturers just now appointed : — Readers — Compara- 

 tive Philology, Dr. Peill ; Botany, Dr. Vines. University 

 Lecturers — Comparative Philology, Mr. E. S. Roberts ; Sans- 

 krit, Mr. Neil ; Mathematics, for Part 3 of the Tripos, Division 

 A, Mr. Forsyth ; Division B, Mr. Hobson ; Division C, Mr. 

 Glazebrook ; Division D, Mr. J. J. Thomson ; Applied Mecha- 

 nics, Mr. Macaulay ; Botany, Mr. F. Darwin ; Animal Morpho- 

 logy, Mr. A. Sedgwick ; Advanced Physiology, Dr. Gaskell and 

 Mr. Lea ; Histology, Mr. Langley ; Geology, Mr. D. Roberts ; 

 Moral Science, Mr. Keynes. 



Prof. Colvin has presented to the Fitzwilliam Museum between 

 eight and nine hundred books on Classical Archaeology, on behalf 

 of certain members of the University, to be deposited in the 

 library of the Museum of Classical Archaeology. 



A warm discussion arose on the 30th ult. in the Arts School, 

 on the Report recommending the erection of new lecture-rooms 

 and work-rooms for Biology and Physiology. Mr. Huddleston 

 said the estimate of 3000'. a year ago had grown to 10,000/. 

 now. Pie had hoped that finality was reached last year. Mr. 

 Oscar Browning objected to the proposals that they were reck- 

 less and extravagant. Why not ventilate the present lecture- 

 rooms, if they were so much used as was described ? The pro- 

 posal to buy 150 microscopes for 1000/. was one of the most 

 ridiculous he ever heard of. Why should not each student bring 

 his own? A science man's library was exceedingly small and 

 inexpensive. Mr. Mayo thought sufficient accommodation might 

 be provided by using the Museum of Zoology as a lecture-room for 

 large classes. Mr. Sedgwick described the inconveniences felt in 

 the late course of Elementary Biology, when 206 men had to pack 



